Gateway Addr Has Changed, Wireless Connections Cannot Obtain IP Addr.

[mcdowelf]

Owned this model Router/Modem for about four months. Came home from work one day, and it looks like the power had gone out, as my machine was stuck in a POST screen talking about my power supply unexpectedly cutting power. I'm not sure if that's related.

Now, my default gateway is no longer 192.168.0.1, but instead the actuall IP address assigned to my router by my ISP. I can only connect one device at a time, and I can't access the machine's firmware web portal through the gateway IP address. If I try connecting from my XBox at home, the error message is that it can not resolve DNS, and my mobile devices authenticate but can't get an IP address. I've tried resetting to factory defaults on the router and reformatting my hard drive, and it seems to go back to normal as long as I don't plug the coax cable in from the NID. I've called my ISP for troubleshooting but they stop me as soon as they find out I'm not on one of their modems. Suggestions?

Thanks in advance.

[mcdowelf · Accepted solution]

Found the answer to this.

The tier-1 support from my ISP originally refused to work on this issue because they would not support my personally owned modem/router. When I contacted live chat support for my ISP and described to the agent the issue, they escalated it to tier-2. 

I recieved a phone call from a local tech the next day who told me that personally owned devices by default are assigned "passthrough" by the ISP. The setting forces a disabling of NAT so that if someone has, say a linksys wireless router attached a to a modem, both machines won't do routing. The setting was correct a few months ago when I called in to have my personal router set by the ISP, but at some point over the Christmas weekend that setting was lost. So they changed a value on their end and it worked fine. I just had to wait a while to get someone who knew what they were doing there.

[mcdowelf]

It would appear I can not edit the above post.

The model is a CG3000v2.

The limitation of only one connected item at a time seems to be clarified to: It only connects to one device at all - my main workstation. Connecting a laptop with the network cable doesn't work either - The laptop can't identify the network and has an APIPA address.

[mcdowelf · Accepted solution]

Found the answer to this.

The tier-1 support from my ISP originally refused to work on this issue because they would not support my personally owned modem/router. When I contacted live chat support for my ISP and described to the agent the issue, they escalated it to tier-2. 

I recieved a phone call from a local tech the next day who told me that personally owned devices by default are assigned "passthrough" by the ISP. The setting forces a disabling of NAT so that if someone has, say a linksys wireless router attached a to a modem, both machines won't do routing. The setting was correct a few months ago when I called in to have my personal router set by the ISP, but at some point over the Christmas weekend that setting was lost. So they changed a value on their end and it worked fine. I just had to wait a while to get someone who knew what they were doing there.